Windows installer: In the Start menu IDLE shortcut, explictly invoke the

pythonw.exe we just installed.  Making Windows key off the .pyw extension
instead screws people with multiple Python installations (reported more
than once on c.l.py).

PCbuild/python20.wse

@@ -1160,8 +1160,9 @@ item: If/While Statement
   Flags=00001010
 end
 item: Create Shortcut
-  Source=%MAINDIR%\Tools\idle\idle.pyw
+  Source=%MAINDIR%\pythonw.exe
   Destination=%GROUP%\IDLE (Python GUI).lnk
+  Command Options=%MAINDIR%\Tools\idle\idle.pyw
   Working Directory=%MAINDIR%
   Key Type=1536
   Flags=00000001